1. Field of the Invention
The present invention relates to an imaging device, an image processing device and the like with respect to an adjustment method of a video signal.
2. Description of the Related Art
A great number of imaging devices such as surveillance cameras, DVD (Digital Versatile Disc) cameras or the like have conventionally had auto-focus functions therein for performing focus adjustment automatically. One of focusing methods in such auto-focus functions is a contrast method to perform focus adjustment by utilizing a fact that an in-focus state (just focus) is caused in a position where a contrast signal of an imaged picture shows the maximum amplitude.
In the imaging devices, the imaged picture comes into de-focus or focus by traveling a focus-lens in its optical axis direction, then the amplitude of the contrast signal also varies accordingly. In the case of the most fundamental contrast method, the focus-lens is traveled in its optical axis direction first of all, thereafter, a direction in which a target object comes into focus is detected based on an amplitude difference between the contrast signal before the focus-lens is traveled and the contrast signal after the focus-lens is traveled, accordingly, the focus-lens is traveled to the detected in-focus direction (e.g., see JP H11-136562 A).